Process of electrically heating articles



No. 752,357. PATENTED FEB. 16, 1904. E. P. PRICE. PROCESS OFELEGTRICALLY HEATING ARTICLES.

APPLIQATION FILED NOV.5, 1902.

N0 MODEL.

Jay.

UNITED STATES Patented February 16, 1904.

PATENT OEEIcE.

EDGAR F. PRICE, OF NIAGARA FALLS, NEIV YORK, ASSIGNOR TO UNION CARBIDECOMPANY, OF NIAGARA FALLS, NEIV YORK, A CORPORATION OF VIRGINIA.

PROCESS OF ELECTRICALLY HEATING ARTICLES.

SPECIFICATION forming part of Letters Patent No. 752,357, dated February16, 1904.

Application filed November 5, 1902. Serial No. 130,182. (No model.)

To all whom it may concern.-

Be it known that I, EDGAR F. PRICE, a citizen of the United States,residing at" Niagara Falls, in the county of Niagara and State of 5 NewYork, have invented certain new and useful Improvements in Processes ofElectrically Heating Articles, of which the following is aspecification.

This process is primarily intended for bak:

: ing the carbon bars which are used as electrodes in carbid and otherelectric furnaces, but may be employed for baking or heating otherarticles.

In carrying out the process the green or partially-baked carbon bars orother articles are arranged around or in proximity to aresistance-conductor and are embedded in or otherwise placed in contactwith a layer of material which is normally a poor conductor ofelectricity, but which will become a good conductor when heated. Theresistance-conductor, articles, and packing are so arranged withreference to the electrodes or terminals of the furnace in which theyare placed that the electric current will in the first instance passmainly or entirely through the resistance core or conductor, but willthereafter shunt through the packing material, as it is converted into abetter conductor by the heat generated in the 3 core.

The invention will be more easily understood by reference to theaccompanying drawings, in which' Figure 1 is a vertical longitudinalcentral 3; section of an electric furnace with the core, articles, andpackings in position; and Fig. 2 is a transverse vertical section online II II of Fig. 1.

The furnace chosen for illustration is a rec- 4 tangular structurehaving side walls 1 and a hearth 2, of refractory non-conductingmaterial, such as fire-brick. Electrodes 3 l extend through the endwalls of thefurnace. These electrodes may each consist ofa group ofcarbon blocks 5, inclosed at. their outer ends in a metal casing 6, towhich is secured the electric terminal 7. The end of each electrodeprojects slightly into the furnace inclosure and may be protected fromwear by a molded carbon block or facing 8. In employing this furnace tocarry out the process a number of the articles to be heated or baked(here shown as rectangular carbon bars 9) are placed on the hearth andalong the side walls of the furnace, being separated from each other andsurrounded by a filling or packing 10 of material which, as stated, willnormally conduct little or no electricity, but whose resistance will belargely diminished when it is subjected to heat. Finely-pulverizedanthracite coal has been found to be a suitable material for thispacking. If the bars to be heated are of less length than that of thefurnace, two or more of them may be placed end to end, as shown. Thebars or other articles may or may not be placed in contact with eachother and with the furnace-electrodes. A resistance-core 11, which maybe of broken coke, is arranged centrally within the rows of articles tobe heated, these articles being placed around the core, so as toentirely in close it. A loose filling 12, of granular nonconductingmaterialsuch as lime, magnesia, or sandis placed between the hearth andside walls and the charge and also overlies the charge and closes thetop of the furnace.

When the furnace has been charged and an electric current is passedbetween its electrodes 3 l, the whole or a major portion of the currentfirst passes through the central resistance-core, which soon becomesheated to incandescence. The articles which lie next the core willthereby be heated to the requisite temperature; but those in the outerlayer or layers will not be sufliciently heated. The

packing of anthracite coal, however, between the rows of articles willbe converted into a conductor by the heat from the central 'co're, andas this packing extends into contact with the electrodes or theirconductive facing 8 a considerable portion of the current will be di'verted from the central core and through these packings. As each articleor row of articles is lnclosed in a packmg, thehcat generated by thecurrent shunted through the packing will suffice to heat the articleswhich lie at some distance from the central core to the desiredtemperature. If the articles lie in contact with each other and with thefurnace-electrodes, a certain portion of the current may also passthrough them and assist in the heating, as the articles will generallybe of such material that their conductivity will increase as theirtemperature rises.

The process may be carried out by the use of furnaces which are widelydifierent from that shown, and in some cases the inelosing walls may beentirely omitted. The central core may be circular or rectangular incrosssection or of any other desired form. The articles may be arrangedaround the core in any desired number of concentric or other layers. Thepacking may be of bituminous coal of high resistance, pulverized carbon,or other suitable material.

I claim- 1. The process of electrically heating articles, which consistsin interposing between different portions of the electrodes or terminalsof a source of electric current direct-current paths comprising aresistance-conductor and a separate layer of material which is normallya poor conductor of electricity but is converted into a better conductorby heat, arranging the articles to be heated in proximity both to saidconductor and layer, and passing an electric current directly throughthe resistance-conductor, thereby initially heating the articles andlayer of poorly-conducting material, converting said layer into a betterconductor, and causing electric current to pass directly through thelayer of material which has been converted into a better eonductor andthereby supplying further heat to the articles, as set forth.

2. The process of electrically heating articles, which consists ininterposing between different portions of the electrodes or terminals ofa source of electric current direct-current paths comprising aresistance-conductor and a separate layer of material which is normallya poor conductor of electricity but is converted into a better conductorby heat, arranging the articles to be heated around said conductor andin proximity to said layer, and passing an electric current directlythrough the resistanceconductor, thereby initially heating the articlesand layer of poorly-eonducting material, converting said layer into abetter conductor, and causing electric current to pass directly throughthe layer of material which has been converted into a better conductorand thereby supplying further heat to the articles, as set forth.

3. The process of electrically heating articles, which consists ininterposing between different portions of the electrodes or terminals ofa source of electric current direct-current paths comprising aresistance-conductor and a separate layer of material, which is normallya poor conductor of electricity but is converted into a better conductorby heat, arranging the articles to be heated around said conductor andwithin said layer, and passing an electric current directly through theresistance-conductor, thereby initially heating the articles and layerof poorly-conducting material, converting said layer into a betterconductor, and causingelectric current to pass directly through thelayer of material which has been converted into a better conductor andthereby supplying further heat to the articles, as set forth.

4. The process of electrically heating articles, which consists ininterposing between dif- 'ferent portions of the electrodes or terminalsof a source of electric current direct-ciu'rent paths comprising aresistanee-conductor and separate layers of a material which is normallya poor conductor of electricity but is converted into a better conductorby heat, arranging the articles to be heated around said conductor andbetween said layers, and passing an electric current directly throughthe resistance-conductor, thereby initially heating the articles andlayers of poorly-eonducting material, converting said layers into abetter conductor, and causing electric current to pass directly throughthe layers of material which have been converted into a better conductorand thereby supplying further heat to the articles, as set forth.

5. The process of electrically heating articles, which consists ininterposingbetwecn different portions of the electrodes or terminals ofasource of electric current direct-current paths comprising aresistance-conductor and a separate layer of material which is normallya poor conductor of electricity but is converted into a better conductorby heat, arranging the articles to be heated end to end and in proximityboth to said conductor and layer, and passing an electric currentdirectly through the resistance-conductor, thereby initially heating thearticles and layer of poorlyconducting material, converting said layerinto a better conductor, and causing electric current to pass directlythrough the layer of material which has been converted into a betterconductor and thereby supplying further heat to the articles, as setforth.

6. The process of electrically heating articles, which consists ininterposing between different portions of the electrodes 01' terminalsof a source of electric current direct-current paths comprising aresistance-conductor and a separate layer of material which is normallya poor conductor of electricity but is converted into a better conductorby heat, arranging the artieles to be heated end to end and around saidconductor and in proximity to said layer, and passing an electriccurrent directly through the resistanceconductor, thereby initiallyheating the articles and layer of poorly-conducting material, convertingsaid layer into a better conductor, and causing electric current to passdirectly through the layer of material which has been converted into abetter conductor and thereby supplying further heat to the articles, asset forth.

7. The process of electrically heating articles, which consists ininterposing between different portions of the electrodes or terminals ofa source of electric current direct-current paths comprisingaresistance-conductor and a separate layer of material which is normallya poor conductor of electricity but is converted into a better conductorby heat, arranging the articles to be heated end to end and around saidconductor and within said layer, and passing an electric currentdirectly through the resistance-conductor, thereby initially heating thearticles and layer of poorly-conducting material, converting said layerinto a better conductor, and causing electric current to pass directlythrough the layer of material which has been converted into a betterconductor and thereby supplying further heat to the articles, as setforth.

8. The process of electrically heating arti cles, which consists ininterposing between different portions of the electrodes or terminals ofa source of electric current direct-current paths comprising aresistance-conductor and separate layers of a material which is normallya poor conductor of electricity but is converted into a better conductorby heat, arranging the articles to beheated end to end and around saidconductor and between said layers, and passing an electric currentdirectly through the resistance conductor, thereby initially heating thearticles and layers of poorly conducting material, converting saidlayers into a better conductor, and causing electric current to passdirectly through the layers of material which have been converted into abetter conductor and thereby supplying further heat to the articles, asset forth.

9. The process of electrically baking carbon articles, which consists ininterposing between different portions of the electrodes of terminals ofa source of electric current directcurrent paths comprising aresistance-conductor and a separate layer of material whichis normally apoor conductor of electricity but is converted into a better conductorby heat, arranging the articles to be heated in proximity both to saidconductor and layer, and passing an electric current directly throughthe resistance-conductor, thereby initially heating the articles andlayer of poorly-conducting material, converting said layer into a betterconductor, and causing electric current to pass directly through thelayer of material which has been converted into a better conductor,thereby supplying suflicient heat to bake the articles, as set forth.

10. The process of electrically baking carbon articles, which consistsin interposing between different portions of the electrodes or terminalsof asource of electric current directcurrent paths comprising aresistance-conductor and a separate layer of material which is normallya poor conductor of electricity but is converted into a better conductorby heat, arranging the articles to be heated around said conductor andin proximity to said layer, and passing an electric current directlythrough the resistance conductor, thereby initially heating the articlesand layer of poorly-conducting material, converting said layer into abetter conductor, and causing electric current to pass directly throughthe layer of material which has been converted into a better conductor,thereby supplying sufficient heat to bake the articles, as set forth.

11. The process of electrically baking carbon articles, which consistsin interposing between different portions of the electrodes or terminalsof a source of electric current directcurrent paths comprising aresistance-conductor and a separate layer of material which is normallya poor conductor of electricity but is converted into a better conductorby heat, arranging the articles to be heated around said conductor andwithin said layer, and passing an electric current directly through theresistance-conductor, thereby initially heating the articles and layerof poorly-conducting material, converting said layer into a betterconductor, and causing electric current to pass directly through thelayer of material which has been converted into a better conductor,thereby supplying suflicient heat to bake the articles, as set forth.

12. The process of electrically baking carbon articles, which consistsin interposing between different portions of the electrodes or terminalsof a source of electric current directcurrent paths comprising aresistance-conductor and a separate layer of material which is normallya poor conductor of electricity but is converted into a better conductorby heat, arranging the articles to be heated end to end and in proximityboth to said conductor and layer, and passing an electric currentdirectly through the resistance-eonductor, thereby initially heating thearticles and layer of poorlyconducting material, converting said layerinto a better conductor, and causing electric current to pass directlythrough the layer of material which has been converted into a betterconductor, thereby supplying sufficient heat to bake the articles, asset forth.

In testimony whereof I afiix my signature in presence of two witnesses.

EDGAR F. PRICE.

Witnesses:

D. \VooDHoUsE, F. B. OCoNNoR.

l'tis hereby certified that in Letters Patent No. 752,357, grantedFebruary 16, 1901, upon the application of Edgar F. Price, of NiagaraFalls, New York, for an improvement in Processes of Electrically HeatingArticles, errors appear in the printed specification requiringcorrection, as follows: In lines 26-7, 45-6, 64-5, 83%, 102-3, and 1212,page 2, and in lines 10-11, 29-30, 48%), 678, 86-7, and 105-6, page 3,the Words direct-current paths should read direct current-paths; andthat the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 15th day of March, A. 1)., 1904.

[SEAL] F. I. ALLEN,

Commissioner of Patents.

in Letters Patent 01 7 l t l's h ereby certified that in Letters PatentNo. 752,357, granted February 16,1904, upon the application of Edgar F.Price, of Niagara Falls, New York, for an improvement in Processes ofElectrically Heating Articles, errors appear in the printedspecification requiring correction, as follows: In lines 26-7, 45-6,64-5, 83 1, 102-8,

and 121-2, page 2, and in lines 1011, 29-30, 489, 67-8, 867, and 1056,page 3, the words direct-current paths should read direct current-pathsand that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Ofiice.

Signed and sealed this 15th day of March, A. 1)., 1904. v

' F. I. ALLEN,

Commissioner of Patents.

